Phase changer



De 22, 1953 A. G. CLAVIER ET AL PHASE CHANGER Filed May 20, 1950INVENTORS ANDRE c1. cLAv/ER y @Av/0 L. THOMAS BY ATTO R N EY PatentedDec. 22, i 1953 UNITED STATES ArEN-'r oFFIce PHASE CHANGER ApplicationMay 20, 1950, Serial No. 163,298

Claims.

This invention relates to microwave transrmssion systems employingsurface wave propagatlon and more particularly to phase Shifters forsuch systems.

In our copending application, Serial No. 163,581, filed May 23, 1950, Wedisclose various forms of guide lines together with associated launchingand receiving devices for surface wave propagation of microwave energy.The guide line may comprise either a bare conductor having a niteresistivity or a conductor with dielectric material distributedtherealong, either as a continuous coating or as spaced sections orbeads. The larger part of the electromagnetic field for such lines isconfined in the form of a cylindrical volume closely adjacent thesurface of the conductor thereby resulting in efficient transmission ofhigh frequency energy. By Way of example, an ordinary No. i2 enameledcopper Wire has been found to have for high frequencies the majorportion of the electromagnetic field concentrated within a 3 to i inchradius about the wire. The high frequency energy has been found to flowin this eld along the surface of the wire with very low loss and to besubstantially free from electrical and other disturbances where thisconfined cylindrical field was substantially unobstructed.

One of the objects of this invention is to provide a phase shifter forguide lines capable of surface wave transmission; and a further objectis to provide a phase shifter for such lines which is easily adjustable.

The phase shifters according to our invention comprise a line conductoralong which conductor sections of cross-sectional size greater than thecross-sectional size of the line conductor are periodically disposed.These conductor sections are similar to the conductor sections of thefilters disclosed in our copending application, Serial No. 152,132,filed March 27, 1950, except that the sections in the present inventionare adjustable in size. These periodically disposed conducting sectionsincrease the delay of propagation of high frequency energy, the degreeof delay depending upon the ratio between the size or thickness axiallyof the sections and the spacing between the sections. By altering thisratio without changing the periodicity of the sections, wide band phasechange is obtainable.

One of the features of the invention is the structural arrangement ofthe conducting sections. Each section preferably comprises a pair ofdisc-like elements at least one of which is provided with a peripheralange disposed concentrically. about the 'line'v conductor inover-.lapping 2 contact relationship with the peripheral edge of theother element of the pair. By adjusting one of the elements relative tothe other dilferences in phase may be obtained.

Another feature of the invention is the manner by which the conductorsections may be adjusted in axial size. In one embodiment of theinvention a corresponding element of each pair is connected together sothat the connected elements may be moved in unison relative to the otherelements which are carried by the line conductor. The connecting meansfor the movable elements may comprise a hollow cylinder of insulatingmaterial disposed about the sections and mounted for axial movementrelative to the line conductor. One element of each section is connectedby insulating means to the hollow insulating cylinder so that movementof the hollow cylinder will produce variation in the size of theconductor sections. To minimize undue perturbation of the high frequencyenergy the ends of the cylinder are closed about the line conductor bybodies of insulating material which preferably are tapered from theouter cylinder to substantially the surface of the line conductor. Aliquid dielectric is also preferably contained within the cylinder, thedielectric coefficient of the liquid being substantially the same as thedielectric coemcient of the insulating bodies.

In still another embodiment, the corresponding elements of each sectionare shifted by means of an axial connector disposed within the lineconductor which in this embodiment is made hollow.

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood, by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

Fig. 1 is a viewin longitudinal section illustrating a phase changerembodying a plurality of phase changer sections together with anenclosing insulating cylinder by which the sections may be adjusted inaxial size;

Fig. 2 is a cross-sectional View taken along line y2f-25fo:l1iig.1;

Fig.` Bris a longitudinal sectional view of a modified form of phasechanger which includes an electrical control for effecting adjustment ofthe sections;

l Fig. 4 is a sectional view taken along line 4 4 of Fig. 3;A

Fig.5 is a fragmentary sectional view illustratinga manual 4controlwhich be L'substituted 5. A phase` chamber according to claim 4, Numberwherein said supporting means include a liquid 2,236,102 tight glandabout said line conductor and a liquid 2,419,855 dielectric is containedin the space between said 2,438,795 line conductors and said cylinder. 5A 2,451,258

ANDR G. CLAVIER. 2,500,875 DAVID L. THOMAS. 2.567.748

References Cited in the le of this patent UNITED STATES PATENTS 10Number Name Date pp. 198-203.

2,215,582 Goldstine Sept. 24, 1940 6 Name Date Kolster Mar. 25, 1941vRoosenstine Apr. 29, 1947 Wheeler Mar. 30, 1948 Trevor Oct. 12, 1948Schupbach Mar. 14, 1950 White Sept. 11, 1951 OTHER REFERENCES Principlesand Practice of Wave Guides,

L. G. H. Huxley, 1947, MacMillan Co., N. Y.,

